1. Field of the Invention
Exemplary embodiments of the present invention relate to a urea solution after-treatment system, and, particularly, to a urea solution after-treatment system, and a method and controller for warning of a urea solution state using a touch, capable of strongly informing a driver of urea solution shortage, urea solution exhaustion, urea solution failure, etc. from a touch recognition pattern of an accelerator pedal.
2. Description of Related Art
Various methods are applied to reduce NOx contained in exhaust gas of a vehicle. As an example for reduction of NOx, there is an after-treatment technology using a urea solution (CO (NH2)2+H2O).
Such a urea solution after-treatment technology may reduce NOx using 2NO+2CO (or HC)->N2+2CO (reaction formula) by which the urea solution is transformed into ammonia (NH3) and then the ammonia selectively reacts with NOx through an SCR catalyst.
To this end, the urea solution after-treatment technology includes a urea solution tank storing ammonia in the form of a urea solution which is harmless to the human body, a selective catalytic reduction (hereinafter, referred to as “SCR”), and an injector for injecting the urea solution into the SCR.
Meanwhile, the urea solution after-treatment technology should meet urea related regulations. As an example, the United States Environmental Protection Agency defines that a vehicle having a non-operational diesel pollution control system fails. In a vehicle equipped with the SCR, the exhaustion of the on-board urea supply is a factor which causes the vehicle to be not driven.
For this reason, the urea solution after-treatment technology further includes a urea solution diagnostic system which allows a vehicle itself to diagnose whether or not a urea solution is insufficient or faulty during driving thereof, and then informs a driver of when the urea solution is abnormal or has trouble, so as not to drive the vehicle.
According to the urea solution after-treatment technology as described above, it may be possible to prevent environmental pollution and an offense against the relevant regulations caused by emission of NOx in exhaust gas without sufficient removal thereof during driving of the vehicle. Particularly, it may be possible to meet Urea-SCR related regulations of North America or Europe by visually informing a driver of urea solution exhaustion and urea solution failure.
However, when a driver merely visually recognizes urea solution exhaustion and urea solution failure, the driver focused on driving of the vehicle has a high possibility of just ignoring a generated urea solution warning message. Moreover, the vehicle may stop against a driver's intention by entering a condition of requiring replenishment of the urea solution, such as full exhaustion of the urea solution or sensing of urea solution failure, in a state in which the driver does not recognize a continuous urea solution warning. The driver, which does not predict such a situation, may feel significantly uncomfortable, resulting in dissatisfaction at the urea solution system. Furthermore, the dissatisfaction at the urea solution system may lead to dissatisfaction at the vehicle.
Particularly, since the BIN #5 exhaust gas regulations of North America require more strictness for a reduction of NOx in exhaust gas, an active measure is required to solve urea solution shortage, urea solution exhaustion, urea solution failure, etc. in the vehicle.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.